Different retrieval mechanisms of overgeneral autobiographical memory for positive and negative cues in remitted major depressive disorder.

BACKGROUND AND OBJECTIVES: Overgeneral autobiographical memory (OGM) has been shown to occur in depressed and previously depressed populations regardless of the emotional valence of cues. However, recent research has pointed out that the retrieval process underlying OGM, generative retrieval (i.e., retrieval requiring effort or additional information) or direct retrieval (i.e., memory that comes to consciousness without effort or additional information), may differ depending on the emotional valence of cues. We examined the hypotheses that a remitted MDD (major depressive disorder), group compared with a control group, would show (a) more direct retrieval of categoric memories for negative cues, (b) more generative retrieval of categoric memories for positive cues, and (c) less direct retrieval of specific memories for positive cues. METHODS: A remitted clinical MDD group (n = 21) and control group (n = 21) completed the Autobiographical Memory Test with minimal instruction, and were required to subjectively judge generative retrieval and direct retrieval. RESULTS: As expected, results showed that the remitted MDD group reported more frequent direct retrieval of categoric memory for negative cues and more generative retrieval of categoric memory for positive cues than the control group. LIMITATIONS: Our paradigm for distinguishing between generative and direct retrieval relied on subjective judgements. CONCLUSIONS: This extends the findings from student sample in previous studies to a help-seeking population. Increased availability of negative categoric memories and the attenuation of positive specific recall represent vulnerabilities for MDD. We discuss how these findings provide further rationale for memory therapeutics for MDD and refinement of those techniques.

Cue Valence Influences the Effects of Cue Uncertainty on ERP Responses to Emotional Events.

Individuals often predict consequences, particularly emotional consequences, according to emotional or non-emotional signals conveyed by environmental cues (i.e., emotional and non-emotional cues, respectively). Some of these cues signify the consequences with certainty (i.e., certain cues), whereas others do not (i.e., uncertain cues). Several event-related potential (ERP) studies regarding non-emotional cues have suggested that the effects of cue uncertainty on attention to emotional events occur in both perception and evaluation processes. However, due to the limitations of previous studies, it is unclear what the effects of cue uncertainty would be in an emotional cue condition. Moreover, it is uncertain whether the effects of cue uncertainty are affected by cue valence (i.e., emotional and non-emotional cues). To address these questions, we asked participants to view cues and then to view emotional (positive or negative) pictures. The cues either did or did not indicate the emotional content of the picture. In the emotional cue condition, happy and fearful faces were used as certain cues indicating upcoming positive and negative pictures, respectively, and neutral faces were used as uncertain cues. In the non-emotional cue condition, scrambled faces outlined in red and blue indicated upcoming positive and negative pictures, respectively, and scrambled faces outlined in green served as uncertain cues. The results showed that for negative pictures, ERP responses in a time range between 60 and 1,000 ms were shifted to a more negative direction in a certain condition than in the uncertain condition when the cues were emotional. However, the effect was the reverse for positive pictures. This effect of cue uncertainty was similar in the non-emotional cue-negative condition. In contrast, there was no effect of cue uncertainty in the non-emotional cue-positive condition. Therefore, the findings indicate that cue uncertainty modulates attention toward emotional events when the events are signified by emotional cues. The findings may also suggest that cue valence modulates the effects of cue uncertainty on attention to emotional events.